// SPDX-License-Identifier: GPL-2.0
#include <linux/kmsg_dump.h>
#include <linux/spinlock.h>
#include <linux/console.h>
#include <linux/string.h>
#include <shared/init.h>
#include <shared/kern.h>
#include <os.h>

static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
                                struct kmsg_dump_detail *detail)
{
        static struct kmsg_dump_iter iter;
        static DEFINE_SPINLOCK(lock);
        static char line[1024];
        struct console *con;
        unsigned long flags;
        size_t len = 0;
        int cookie;

        /*
         * If no consoles are available to output crash information, dump
         * the kmsg buffer to stdout.
         */

        cookie = console_srcu_read_lock();
        for_each_console_srcu(con) {
                /*
                 * The ttynull console and disabled consoles are ignored
                 * since they cannot output. All other consoles are
                 * expected to output the crash information.
                 */
                if (strcmp(con->name, "ttynull") != 0 &&
                    console_is_usable(con, console_srcu_read_flags(con), true)) {
                        break;
                }
        }
        console_srcu_read_unlock(cookie);
        if (con)
                return;

        if (!spin_trylock_irqsave(&lock, flags))
                return;

        kmsg_dump_rewind(&iter);

        printf("kmsg_dump:\n");
        while (kmsg_dump_get_line(&iter, true, line, sizeof(line), &len)) {
                line[len] = '\0';
                printf("%s", line);
        }

        spin_unlock_irqrestore(&lock, flags);
}

static struct kmsg_dumper kmsg_dumper = {
        .dump = kmsg_dumper_stdout
};

static int __init kmsg_dumper_stdout_init(void)
{
        return kmsg_dump_register(&kmsg_dumper);
}

__uml_postsetup(kmsg_dumper_stdout_init);